Diaper Side Seam Margin Design for Touch Comfort

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Solution Overview

Problem

Pants-type disposable diapers cause discomfort when the joining portions, which are hard and have multiple fusion points, are touched during wearing or putting on, as the fingers may directly contact these points, and reducing the fusion area compromises joining strength.

Innovation Solution

The absorbent article features a joining portion divided into upper and lower parts with varying tensile stress and margin dimensions, where the upper part has a larger margin to cover fusion portions, enhancing cushioning and maintaining high joining strength by adjusting the size and shape of fusion portions and margins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the area of fusion portions is reduced to restrict discomfort, then comfort is improved, but joining strength decreases

Engineering Contradiction:
Improvediscomfort from touching fusion portionsVSAvoidjoining strength of joining portion
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent applies local quality by creating different margin dimensions in different regions of the joining portion. The upper joining part (where fingers naturally contact) has a larger margin dimension to cover fusion portions and prevent discomfort, while the lower joining part has a smaller margin dimension to maintain joining strength. This spatial differentiation of properties resolves the contradiction between comfort and strength.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If the dimension of margin is increased to cover fusion portions, then comfort is improved, but the structure becomes more complex

Engineering Contradiction:
Improvediscomfort from touching joining portionVSAvoidstructure of joining portion
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Instead of uniformly increasing the margin dimension throughout the entire joining portion, the patent applies local quality by increasing the margin dimension only in the upper joining part where finger contact occurs. The lower joining part maintains its original structure, thus improving comfort without unnecessarily complicating the overall structure.

Inventive Principle:
Principle #3Local quality

3Strength

If the area of fusion portions is increased to maintain joining strength, then strength is improved, but discomfort increases

Engineering Contradiction:
Improvejoining strength of joining portionVSAvoiddiscomfort from touching fusion portions
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent segments the joining portion into an upper joining part and a lower joining part based on functional requirements. The upper part has enlarged margin dimension to cover fusion portions and prevent discomfort, while the lower part maintains smaller margin dimension to preserve joining strength. This segmentation allows different areas to have different properties optimized for their specific functions.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design prevents discomfort by covering fusion portions with a larger margin while maintaining high joining strength, ensuring the absorbent article is comfortable to wear and use without compromising its integrity.

Implementation Method 1

the joining portion is elastic in the lateral direction, tensile stress in the lateral direction in the upper joining part is larger than tensile stress in the lateral direction in the lower joining part

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3804677B1Absorbent article
Publication Date: 2023.10.11 UNI CHARM CORP
  • EP3804677B1 patent drawingFigure 1
  • EP3804677B1 patent drawingFigure 2
  • EP3804677B1 patent drawingFigure 3

AI summary

A pant-type disposable diaper (1) intended to restrict a wearer or a caregiver from feeling discomfort when touching a joining portion while maintaining a joining strength in an upper joining part relatively high includes a stomach-side portion (2) and a back-side portion (3) that are joined to each other with a joining portion (5L). The joining portion is formed by joining an end portion (2L) of the stomach-side portion in a lateral direction (W) and an end portion (3L) of the back-side portion in the lateral direction that are overlapped on each other such that inner surfaces face each other with a plurality of fusion portions (11) aligned in a longitudinal direction (L) at intervals. Tensile stress in the lateral direction in the upper joining part (P5U) of the joining portion is larger than tensile stress in the lateral direction in the lower joining part (P5L) of the joining portion. A dimension of a margin (12) in the lateral direction in the upper joining part is larger than a dimension of the margin in the lateral direction in the lower joining part. An area of each of the fusion portions positioned in the upper joining part is larger than an area of each of the fusion portions positioned in the lower joining part.